Google no longer allows the use of its maps API unless you obtain a key. Pages on domains that used the Google Maps API before June 22, 2016, will continue to work (though it's not known for how long), but a page that's on a domain that didn't formerly use the API will not work properly without a key. A key may be obtained without any cost. Visit the Google developer page and click the Get a Key button. You will have to create a Google account if you don't already have one (also free). Follow the prompts to create a project (you can just accept the default name) and to create a Browser API key. Each of these steps will take some time, so don't get impatient and start clicking things repeatedly.

You may restrict use of the key to just your domain by going to the Google API Manager / Credentials section, and editing the entry for your key. But if you do so, local preview of your album will fail, because the map request will be coming from your PC, rather than from your domain. Restricting use of the key is probably an excess of caution. In theory, someone else could get your key and use it on his or her own site. This would become a problem only if the key were used for more than 25,000 map views per day, a stunningly high number. And even if that happened, it's a simple matter to delete that key, get a new one from Google, and plug it into your album(s).

If you do opt to restrict the use of your key, be very careful about how you enter the domain name. To cover all bases, enter your domain as, for example, &ast;.example.com/&ast; and as example.com/&ast;, each on a separate line. Then wait at least 15 minutes before testing your page - the setting may not take effect immediately. Then, you should build and preview your album without entering your API key. When you have everything the way you want it, enter the API key, click Make Album one more time, then upload the album.

Skins that currently use the Javascript API to display maps include Gromit, Matrix, MatrixSlide, Neptune, Photoblogger, PhotoSwipe, Saturn, Slide Show 4, Tiger, and Turtle, and each provides a place in its settings to enter the key. While Chameleon, FotoPlayer, FotoSlides, Improved Slide Show 3, Minimal, and SimpleViewer also include links to Google maps, they do not use the API and so do not require a key. A few older, unsupported skins include Google map displays - the method used is not known, so test before using these skins.

Google is now tightening the screws further. It will soon no longer be possible to use Google maps without an API key, even for older sites.

More annoying, however, is that as of June 11, 2018, you will need to set up a billing account with Google to continue using your API key. The first $200 worth of map usage each month will be free of charge, and the numbers involved are large enough that it's extremely unlikely that any jAlbum user would actually trigger the need for payment. But Google will still insist that you provide a credit card.

ETA: I'll update this thread sometime after June 11, 2018, once the dust has settled. There is conflicting information out there about whether Google actually intends to force "free" users to provide credit card info, which most commenters seem to recognize is a terrible idea. Any site that says, "This is free, but you have to give us your credit card info" triggers an automatic response from most visitors - they run away, because that's always the sign of a scam. It's surprising that Google seems to be unaware of this. Maybe they'll wise up.

Latest news, as of July 16, 2018. If you already have a free Google maps API key, it appears that you can keep using it without providing billing information to Google. If your usage somehow spikes, and you exceed the "$200 worth free per month" threshhold, your map page may stop working.

Others report, however, that if you now try to sign up for a free API key for the first time, you'll be required to provide a credit card, even though the service is "free."